How to automatically get the result of the 3rd column based on the first two?

Question

PHP

Tell me, the table has 3 columns
FinalPrice, Price, Sale

How to make it so that when Sale is empty, FinalPrice is equal to the Price value, but if we add a value to Sale, then FinalPrice would be equal to the Price * Sale formula?

Those. what would he look for in the table in FinalPrice, and not calculate it just before displaying it on the page.

Answer 1

ALTER TABLE `table`
  ADD COLUMN `FinalPrice` FLOAT 
    AS (IF(`Sale` IS NULL, `Price`, `Price`*`Sale`)) STORED;